Editor's note: The following story deals with sexually-themed subject matter that will not be appropriate for some readers. Discretion is advised.

LAS VEGAS — The man knocks on the hotel room door and is told to come in.

The woman sits on the bed, waiting for her first glimpse of the man she's been sold to for the night.

He comes in and begins unbuckling his belt as he explains what he wants.

Twenty minutes later he gets up and dresses quickly, tossing a wadded pile of bills toward the bed where the woman is still huddled under the sheets.

A few miles down the street, another man tells his wife he needs to finish some work. She goes to bed, and he locks himself in the study, where he turns on his computer and masturbates to pornography for the next three hours.

While society has kept the two behaviors separate, there's really no difference between pornography and prostitution, feminist scholars and anti-porn advocates argue.

"You can't even pull them apart, so I coined the word pornstitution," says Sam Berg, a feminist author and activist in Portland who started the website, JohnStompers.com. "I got tired of trying to explain that they're the same thing."

Pornography and prostitution, as well as every other sex industry activity, share the same three factors: a seller (pimp/producer/manager), a person being sold (prostitute/porn actress/stripper) and a buyer (john/porn viewer/club patron).

And each of these ventures — regardless of differences in legal status, public acceptability, or even the lack of money changing hands — thrives on the objectification of women.

"These are all ways that men buy and sell women's bodies for sexual pleasure," says Robert Jensen, a professor in the school of journalism at the University of Texas at Austin, who has written extensively on pornography.

Yet, there's still a societal disconnect between prostitution, which is viewed as harmful, and pornography, which is seen as "normal, inevitable and harmless," says Rebecca Whisnant, professor of philosophy and director of women's and gender studies at the University of Dayton in Ohio.

"Pornography producers benefit enormously from not being seen as pimps. I think we need to think about whose interest that serves."

But pimps are exactly what they are, says Donny Pauling, a former pornography producer in California who recruited more than 500 women over nine years.

He'd start his recruits at $500 for a few hours of filming, then turn around and use that clip to make more than $3,500.

Pauling said he remembers one fellow producer who set up a scene for a girl he recruited, but Pauling knew she wasn't ready for that type of sex act.

"I stopped him, so she liked us even more because of that," said Pauling. "Just a few weeks later she was doing that same scene and more for us. If this isn't human trafficking, I don't know what it is. This is the same thing that pimps do, but when we do it, it's legal."

Pauling left the industry in 2006 and now travels the country sharing his experiences.

"I just talk about what happens to the people in the business, then point out that the law of supply and demand demonstrates you don't have to be picking up a camera to be ruining lives. You just have to be looking," he said. "That's been effective."

Those who view pornography don’t consider themselves "johns," or men who buy sex, because so often they're not paying for anything and as one addict put it, "I'm walking through a museum, looking at stuff that's already there."

But even walking through that "museum" is supporting an industry that thrives on the objectification and degradation of women, says Jen Cecil, director of After Hours Ministry, a nonprofit outreach program aimed at men and women involved in prostitution in Los Angeles.

"There's not a huge difference in what (porn stars and prostitutes) experience," she said. "They're still getting paid for sex. They're still being demoralized. The abuse runs across both."

Yet in one sense, pornography may actually be worse than prostitution, says Cecil.

"The (viewer) has no interaction with her. He really sees her as just an object," she says. "There's zero concern for the fact that she's a real person, or the (factors) that have brought her there."

Cecil also believes that individuals can become addicted to pornography, and once that happens, they need more to excite them and begin acting out by visiting strip clubs or hiring prostitutes — thus making pornography the catalyst for greater promiscuous behavior.

It's impossible to say definitively that watching pornography causes prostitution use, but it's definitely "part of a cluster of variables that are connected with men's assumption that they are entitled to use women sexually whenever they want," says Melissa Farley, a research and clinical psychologist at Prostitution Research & Education, a nonprofit California-based organization dedicated to research and education surrounding trafficking and prostitution.

Farley and several co-authors studied 110 men who bought sex in Scotland and found that they were more likely than non-sex-buying men to have viewed pornography and to have committed sexual aggression against non-prostituting women.

"Pornography teaches men how to be johns," Farley says. "Pornography is cultural propaganda, which drives home the notion that women are prostitutes. Pornography is pictures of prostitution."

So if prostitution is so problematic, why do women choose it?

"If your kids are hungry and you're trying to feed them, that's not a choice," Farley says. "If a woman doesn't have a place to live because she's escaping a violent boyfriend and it's 10 degrees outside and the only people who offer her a place for the night are pimps and johns who expect sex in exchange for shelter and food. We have women who are prostituting for a tank of gas or cheeseburgers. It's not a choice in the way you and I think of choices. If you look at the data, the people with the least choices in the world are the ones in prostitution."

One man Farley interviewed was a non-sex buyer and described prostitution this way:

"On the face of it, the prostitute is agreeing to it. But deeper down, you can see that life circumstances have kind of forced her into that. It's like someone jumping from a burning building — you could say they made their choice to jump, but you could also say they had no choice."

Which is why arresting a woman for prostitution does nothing to fix the prostitution problem, says Cecil, it only creates more emotional baggage and entangles her in the legal system.

Several Scandinavian countries have adopted the "Nordic Model," which criminalizes johns rather than prostitutes, conducts large public awareness campaigns about the laws and provides exit services to the men and women who need help getting out.

In Sweden, buying sex is a felony, and when Norway criminalized the purchasing of sex in 2009, reported rapes of prostitutes dropped by nearly 50 percent — a huge victory, says Berg, but one that was ignored by pro-prostitution groups because they pointed to massive increases in less serious violence like hair-pulling and biting as evidence of a failed law.

Despite success of the Nordic Model and the prevalence of anti-prostitution laws in most countries, too few laws are actually enforced, Farley says. During interviews of more than 700 sex buyers across five countries Farley and her group hear the same thing: "I know the law isn't going to be enforced against me."

However, in the Scotland study, 89 percent of sex buyers said they would be deterred by being added to a sex offender registry, 84 percent by having their picture and/or name in the local paper and 79 percent by having to spend time in jail, according to a peer-reviewed article published in 2011 in Psychological Trauma: Theory, Research, Practice, and Policy.

"I think moving in that direction is the way to go," Whisnant said. "It expresses in law and in the attitudes of society what the truth of the situation is — it's not a victimless crime. It's not just two happily consenting adults doing whatever. It's some people taking brutal advantage of the extraordinary vulnerability of other people. (We need to) criminalize the people doing the harm, not the people having the harm done to them."